Hey guys I need a little help here.

I am running my 91 Si in SCCA Solo 2's STS class. I want to bump my rev limiter up and am not to confident in the engine running over 7k. I am thinking of refreshing the engine with new pistons, rings, valves, and valve sprngs. Do I need to go in to the bottom end.

What do you guys think

Thanx

 

I would get new cams for a rev that high. stovk ones might be a bad thing to use with a high rev limiter

 

You cant change cams in this class.

 

will the cams make power up that high?

 

deftones0817 is on the right track, the cams don't make any power that high

 

I'm not worried on making more power at that high RPM. I just dont want the engine to blow.

 

I agree probably not worth it on the stock cam. If you want it for those fast courses so that you can stay in 2nd, I say just short shift it into 3rd. Those fast courses are rare because the low hp of the Civic rarely gets you bouncing off 2nd w/ a stock limiter. Worth risking valve float or spun bearings - nah...

 

Well large courses are not that uncommon aroung here. Plus there are rumors that Hankook and Falken will be putting out a 225/??/13. I lost my class this weekend by less than a second and I figure the BMW that beat me pulled me on a 300 yard basicly straight set of gates. So its now time to re build the engine..And I cant change the cam.

 

you will be slower shifting at 8000 since you would make more torque at that point in the next gear. That is what people are trying to say. Not only that, but I would trust the stock springs quite that high.

 

The idea of building up the engine is not to shift. I can tell you that I have talked to many National level drives and seen then drive. It is known in Autox that you use the rev limiter up to 5 hits. Any more than 5 hits and the shift would be faster.

Its slower to take the shift up because then you have to shift back to 2nd.

 

well i'm not into autocrossing and I'm not sure what your trying to accomplish with redline of 9k when you stock cam that you don't want to switch out only makes power to about 6300rpm....

rebuilding a fresh d16a6 to stock specs and upgraded valvetrain to rev to 9k would be pointless. It will put a ***** load of wear and tear on the rings-pistons/walls cause of the por R/S ratio and I would not be supriesed if you had to rebuild it only after less than 5,000 track miles.

 

I understand that this is not a autocross forum. But the car will only hit that high for a second or two. Autocross is not a track event I understand the diffenence there. So that is why I asked if the bottomend needed to be rebuilt. The car has 178k on it, but it will be trailered soon. I just dont want to throw a rod so I guess just to be safe I will plan on doing the bottom end as well.

 

There really isn't anything you can do to change that motor to safely run over the stock rev limit without changing to a different class. You can only replace the internals with oem internals from that motor, so you won't accomplish anything by changing the parts in the lower or upper end. And just doing a rebuild won't change whether the motor can handle going passed the stock rev limit. As far as wanting to carry 2nd gear longer so that you don't have to shift, that doesn't really make much sense. I do autocross and have lots of good drivers up in my region and they just shift into 3rd. I guess what everyone is getting at is really why you would carry a gear way over it's power band - how can keeping the car in a gear out of it's powerband be slower than shifting to a higher gear and keeping in the power band? the best way to get more out of 2nd gear would be to look into putting something like the hf tranny into your si. then the gear ratio would be different enough that you would get something like 80mph out of 2nd gear - that should carry you far enough. but i don't think you can swap tranny's in STS.

 

Stock Si cam will rev to 7100

 

just put in a sohc zc cam, its "stock" just helps a tad more than the si cam, ill have one after my other cam comes back from exospeed

 

I'm not looking to 80 in 2nd. I can tell you that it is faster on a Autox course not to take the shift if you dont have to. I have spoken to National Champion Tim Aro who drives a MR2 prepped for CSP, and he says that its slower to take the shift and have to rev match to get back into 2nd. Things happen way faster on a autox course than road course. And to credit Tim he is a driving instructor for the Evolution Autocross school, he also teaches road racing schools. And when I talked to him last month he said he had just gotten back from somewhere (California I think) testing and teaching for Lexus. So I'm going to take his word.

So just to clarify its not shifting up thats the problem its the down shift thats the problem. Top out at 60+ mph into a very hard left then right at 20 mph all in a distance of 50-60 feet.....I cant rev match that fast. And you can you are the man. But any hesitation and you lost time. And in STS 2 day total times from 1st place to 10th are not much more than a second or two.

 

Use arp rod bolts and the bottom end should be good for a little higher. I run a 2.2 b20vtec with stock honda crank and stock rods and rev it to 8300 with no problem might go to 8500. That is with the arp rod studs. Most hondas that throw rods throw them b/c the bolts break. I am sure that the valve springs are going to need to be up graded but not sure if they are legal in sts.

Kerry

 

I shift my A6 at 7400rpm at least once a day.

 

amen to 96-EJ6 B18C "I shift my A6 at 7400rpm at least once a day."
me too before it got impounded.. but someone on this forum said stock si cams take it to 7100.. what happends when you take it to 7450??

 

hey the guy just wants to rev high, so why not let him

from all the things ive seen, rods tend to go in the D series alot, with oil starvation and other things.
since rods sem to be the weak point, i would upgrade them

and do the arp rod bolts

 

I'm running the PG7 computer (89 Integra 5 speed) in my daily driver 91 Si STS car. From what I've read it allows 7800 RPM's before the limiter. Ran it all last season and several events this season with no problems so far. No promises, but my motor is still together. YMMV, but I'd go ahead and do it. It didn't make any real difference in power, but the extra revs do come in handy sometimes. The bigger problem is that the stock injectors aren't able to handle more than 7800 RPM (according to Zdyne's website) so you might run into misfires if you go above that. Good luck!

 

the power curve runs out right at 7500 rpms, however the stock internals will handle 8500 rpm, we did it in 2002 all year with a fresh head and 120k on the block.
the distributer can only handle 9200 rpm, then it starts to send wrong signals to the cylinders, very expensive. Be careful of the ecu program, the spoon or mugen program work the best, good luck

p.s. sts underdog, get that ecu out of that ca, you will fry your distributer instantly.....

Jason

 

Jason-
Really? I had not heard about any problems with that ECU swap. I know Ryan Thompson is running the same setup. Any other budget ECU suggestions? I've still got the original Si ECU but I'm kind of leery of the "Mugen" chips on eBay for $20. Zdyne would be nice, but it's not in the budget right now. Thanks! Any word on the Subaru trans yet?

 

sniff sniff... I smell REALSPEED...

 

Actually, email todd00, he can get you set up with several different programs, all are well de-bugged. The subaru will be fixed next week, so we will find out what the dillio is....

Jason